The Environmental Protection Department (EPD) has recorded higher than normal pollution levels. At 5pm today (April 24) the Air Quality Health Index (AQHI) at Yuen Long general air monitoring station reached 10, corresponding to the "Very High" health risk category.

The northeast monsoon persists over southern China. The weather is mainly fine with moderate easterly winds. The intense sunshine enhances photochemical smog activities and the formation of ozone, resulting in high pollution in the region. In addition, light winds hinder the effective dispersion of air pollutants and the high level of ozone has promoted the formation of nitrogen dioxide, particularly in parts of the urban areas and at the roadside. It is expected that the AQHIs of some general and roadside air monitoring stations may reach "Serious" level later today.

According to the Observatory, the northeast monsoon now affecting the south China coast will be replaced by a relatively humid maritime airstream early next week.?It is expected that pollution levels will remain higher than normal until then.

With a health risk category in the "Very High" range or above, children, the elderly and persons with existing heart or respiratory illnesses are advised to reduce physical exertion and outdoor activities to a minimum or avoid such activities. The general public is advised to reduce, or reduce to a minimum, outdoor physical exertion, and to reduce time outdoors, especially in areas with heavy traffic. As the health effects of air pollutants may vary for individuals, persons who are in doubt or experience discomfort should seek advice from health-care professionals. The public may visit the website of the Centre for Health Protection (www.chp.gov.hk/en/content/9/460/3557.html) for more information on the health effects of air pollution and relevant health advice.

The Education Bureau (EDB) urges all schools to visit the EDB website for appropriate measures to safeguard students' health and to take note of changes in the index. The relevant hyperlink is as follows: www.edb.gov.hk/en/sch-admin/admin/about-activities/sch-activities-guidelines/index.html.¡@

At the "Very High" level, employers of outdoor workers performing heavy manual work are advised to assess the risk of outdoor work and take appropriate preventive measures to protect the health of their employees, such as reducing outdoor physical exertion and the time of their stay outdoors, especially in areas with heavy traffic. At the "Serious" level, employers of all outdoor workers are advised to assess the risk of outdoor work and take appropriate preventive measures to protect the health of their employees. Members of the public can check the current AQHI readings at the EPD's website (www.aqhi.gov.hk/en.html) or by calling the hotline 2827 8541.